Method and apparatus for non-destructively measuring local resistivity of semiconductors
US5379109A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1992 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Jun 17, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for non-destructively measuring resistivity of a semiconductor, such as InP, comprises light sources for illuminating a preselected portion of the semiconductor with first and second light beams, each of a preselected single wavelength, the first light beam operating to excite the semiconductor by photo injecting carriers, and the second light beam bombarding the local portion of the semiconductor with a preselected photon energy. The apparatus measures a fractional change in reflectance of the second light beam responsive to the first light beam, and records this fractional change in reflectance for various values of photon energy of the second light beam, to generate a photoreflectance line-shape. The photoreflectance line-shape is used to calculate a photoreflectance line-shape phase angle, which is used to determine the resistivity of the preselected portion of the semiconductor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.